Heretofore, a feeding system has been known which is provided with a plurality of injection molding machines and which is for feeding these injection molding machines with a resin material in a batch-type fashion or a continuous fasion.
The following methods (1) through (3) has been heretofore used to feed the resin material to a plurality of the injection molding machines.
(1) An operator manually throws in a resin material from a sack of resin into a hopper at every injection molding machine.
(2) An autoloader or a resin material feeding device is attached to each injection molding machine and feeds a resin material to the injection molding machine. In this case, each of the autoloaders is fed with the resin material by an operator. Thus, the resin material is delivered into each hopper through each autoloader.
(3) A hopper of each injection molding machine is connected to a resin tank by a pipe through which a resin material is transported from the resin tank. In this event, the amount of resin transported from the resin tan is controlled by monitoring an amount of the resin material in the hopper.
However, in the above-mentioned method (1), the operator must manually feed the resin material into the hopper. Furthermore, the operator must continuously monitor the amount of the resin material in the hopper to replenish the resin material therein.
In the method (2), the resin material in the hopper is monitored by the autoloader. However, there remains a problem that the operator must manually feed the resin material to the autoloader.
On the other hand, in the method (3), the resin material is automatically fed from the resin tank to the injection molding machines. Accordingly, the operator can save a lot of labor. However, if there are a large number of injection molding machines and, furthermore, if there are many kinds of resin materials, an extremely large number of pipes must be arranged. This makes it difficult to install the system in a factory.
Accordingly, it is an object of the present invention to provide a material feeding system which is capable of automatically feeding a resin material to injection molding machines and which can readily be installed in a factory.